This invention relates to a method and apparatus for enhancing the signal-to-noise ratio in a suite of seismic traces and more particularly to the enhancement of the primary-to-multiple reflection ratio in the seismic traces.
In seismic exploration, seismic energy is generated at a shotpoint at or near the surface of the earth, is reflected from subsurface interfaces between layers of the earth, and is received by a spread of geophones on the surface of the earth. The geophone signals are recorded in the form of a suite of seismic traces. One common method of seismic exploration is known as common depth point exploration. In this method a number of seismic traces are recorded representing seismic energy reflections from a common reflecting point.
In such common depth point exploration it is the principal object of the geophysicist to obtain an accurate representation of the subsurface layering by interpreting between the common depth point or primary reflection signals and the various noise signals that are also recorded on the seismic traces. Such noise signals may take the form of multiples, ghosts, reverberations, ground roll, shot noise, and other types of distortion. The present invention is particularly useful in common depth point seismic exploration to eliminate multiples from the seismic traces, thereby permitting more accurate interpretation of the subsurface layering.